The invention relates to a device for the advancing of a number of stacks of electrical and/or electronic parts, each of the stacks being accommodated in a tubular magazine, each of the magazines being arranged in at least one grid which as a matrix of openings for accommodating the magazines in a pattern according to which the parts have to be arranged on a printed circuit board.
Devices of the kind forming the subject of the present invention are known per se and form part of devices for the correct positioning of electrical and/or electronic parts on printed circuit boards. These parts are of a prismatic shape and have very small dimensions without connection wires, and are also referred to as parts of the "chip" type. The parts are packed in tubular magazines having an internal cross-section which corresponds to the shape of the parts. A number of this kind of magazines is arranged in one or more grids so that their position corresponds to the positions in which the parts have to be positioned on a printed circuit board. Subsequently, the stacks of parts in the magazines are simultaneously pushed upwards until the uppermost parts have reached a position in which they can be picked up by suitable gripping mechanisms, followed by further alignment and transport to the printed circuit board.
A drawback of a device of the described kind which is known from DE-OS 27 16 330, to which U.S. Pat. No. 4,127,432 corresponds, is that parts of different thickness cannot be simultaneously processed, because the upper edges of the magazines are all situated in one plane and the stacks of parts are advanced over approximately the same step height. This means that in practice only parts having a thickness equal to the step height can be simultaneously processed.
In order to eliminate this drawback, it has already been proposed to move the stacks of parts in the magazines upwards by means of hydraulic pistons which advance the stacks regardless of the thickness of the parts until the upper side of all parts contacts an abutment, so that the upper sides of the parts are at a defined level, thus enabling transfer by suitable means. The complex and hence expensive and vulnerable construction is a drawback of this device.